These do work pretty well in terms of making a room more breathable, but I'm not too sure about the reliability of this particular model. I bought one before and it completely died within a few months. It is also quite noisy, even on the lowest setting, but that seems to be the case with any of these things. This one is a bit bigger than you might expect and hideously ugly if that bothers you.

I bought 2 a couple of weeks ago, and agree with the above, they are rather noisy(although I manage to sleep ok with it on) , but seem to be quite good at what they do. For a larger room, i.e. living room I think you would need something bigger, but I guess it cant hurt ? . Waking up in the bedroom being able to breathe is a godsend though ! lol